Substrate Peripheral Portion Measuring Device, and Substrate Peripheral Portion Polishing Apparatus

ABSTRACT

A projecting/receiving unit ( 52 ) projects a laser light to a peripheral portion ( 30 ) and receives the reflected light while a liquid is being fed to a substrate ( 14 ) and is flowing on the peripheral portion ( 30 ). A signal processing controller ( 54 ) processes the electric signal of the reflected light to decide the state of the peripheral portion ( 30 ). The state of the peripheral portion being polished is monitored. Moreover, the polish end point is detected. A transmission wave other than the laser light may also be used. The peripheral portion ( 30 ) may also be enclosed by a passage forming member thereby to form a passage properly. The peripheral portion can be properly measured even in the situation where the liquid is flowing on the substrate peripheral portion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a substrate peripheral portionmeasuring device for measuring the state of the peripheral portion of asubstrate. The substrate peripheral portion measuring device belongs toa semiconductor wafer peripheral portion polishing apparatus, forexample, and is used to measure the polishing state of the peripheralportion being polished.

2. Background

As miniaturization and high integration of a semiconductor deviceadvance, management of particles becomes more important. One of majorproblems in the management of the particles is the dust formation, whichis caused by the surface roughness to occur on the circumferentialperipheral portion of a semiconductor wafer (or substrate) while thesemiconductor device is being manufactured.

In the semiconductor device manufacturing process, flaws or a number ofminute needle-shaped projections may be formed at the circumferentialperipheral portion of the semiconductor wafer thereby to cause thesurface roughness. The needle-shaped projections are broken to producethe particles while the semiconductor wafer is being transferred orprocessed. These particles lead to a drop in the production yield. Thus,it is necessary to remove the needle-shaped projections from thecircumferential peripheral portion of the semiconductor wafer.

In recent years, moreover, there is a tendency that Cu is used as thewiring material for the semiconductor device and that the Low-k materialis used as an insulating material. When the Cu formed on thecircumferential peripheral portion of the semiconductor wafer sticks tothe arm of a transfer robot or a cassette for housing the substrate, theCu can cause the so-called “cross contamination”, in which it diffusesto contaminate the remaining steps. On the other hand, the very fragileLow-k film leaves the circumferential peripheral portion of thesubstrate during the CMP working treatment thereby to damage or scratchthe pattern face. It is, therefore, important to clear thecircumferential peripheral portion of the semiconductor wafer of the Cuor Low-k film.

As the pattern of the semiconductor wafer becomes highly dense, thesub-micron contamination is deemed as a problem and highlighted as aserious cause for a defect in the wafer process, although not deemedserious in the prior art. Under this background, it is also important topolish off the film or the like of the wafer peripheral portion.

In the general peripheral portion polishing technique of the prior art,the turning wafer is fed with a liquid such as water. A polishing toolsuch as a polishing tape is pushed to the peripheral portion thereby topolish the peripheral portion.

The prior art cannot grasp the state of the peripheral portion beingpolished. Therefore, a total polishing time is determined to manage thepolishing process. In order to determine the total polishing time, thesample wafer is subjected at first to a polishing treatment of aninitial stage, and the wafer end face is then observed by a camerathereby to examine the flaws left in the defective portion. Then, anadditional polishing time necessary for a target finish state iscalculated, and the additional polish is performed. The additionalpolishing time is calculated by using a polishing rate. The additionalpolish and the subsequent camera observation are repeated to determinethe total polishing time. The total polishing time thus obtained isapplied to the subsequent wafer polish.

Moreover, a wafer peripheral portion measuring device has also beenproposed in the prior art. For example, the measurement device ofJP-A-2003-139523 (pages 3 and 4, FIG. 1) illuminates the peripheralportion with a diffusive light to photograph the peripheral portionthereby to detect the defect of the peripheral portion from thephotograph.

In case, however, the total polishing time is determined by means of asample wafer, it takes a remarkably long time to repeat the additionalpolish and the camera observation. Moreover, the total polishing timerequired for the practice is different for each wafer. Even if the totalpolishing time is determined with the sample wafer, the polish may beshort or excessive for another wafer so that the process is notstabilized to lower the productivity.

On the other hand, the wafer peripheral portion measuring device of theprior art has failed to consider the measurement in the presence of aliquid such as water. Therefore, the device of the prior art is notsuited for the measurement in the peripheral portion polishing apparatus(i.e., in-line) and during the polish (i.e., in situ). If the peripheralportion could be measured during the polish in the polishing apparatus,the peripheral portion polishing process could be properly managed toimprove the productivity.

Here, the background art of the invention has been described on thepolish of the wafer peripheral portion. A similar background can applyto purposes other than the peripheral portion polish. For example, thereis desired a technique for measuring the peripheral portion in therinsing process.

DISCLOSURE OF THE INVENTION

The present invention has been conceived under the background thus fardescribed and has an object to provide a peripheral portion measuringdevice for measuring the state of the peripheral portion properly. Thisstate of the peripheral portion typically means the surface roughnessdue to flaws or minute projections, and means that the material used inthe device manufacturing process, such as Cu or a Low-k material as theinsulating material sticks to the surface of the circumferentialperipheral portion of the substrate or forms a film-shaped substance.

According to the invention, there is provided a substrate peripheralportion measuring device for measuring the state of the peripheralportion of a substrate. The substrate peripheral portion measuringdevice comprises: a wave transceiver for transmitting a transmissionwave to the peripheral portion while a liquid is being fed to thesubstrate and is flowing on the peripheral portion, and for receiving areflected wave from the peripheral portion; and a received waveprocessing unit for processing the signal of the reflected wave todecide the state of the peripheral portion. Thus, according to theinvention, the peripheral portion can be properly measured even in thesituation where the liquid flows on the peripheral portion.

Here, the liquid is exemplified by water, and the transmission wave isexemplified by a laser light. The kinds of the liquid and thetransmission wave may not be limited but be within a measurable range.

In the invention, the peripheral portion of the substrate includes abevel portion and an edge portion. The bevel portion is the outercircumference of the substrate, and the edge portion is the two sideportions of the bevel portion (i.e., the end portions of the surface andthe back). The device of the invention may measure the bevel portion,the edge portion or both the bevel portion and the edge portion.Therefore, the later-described peripheral portion treatment includes thetreatments of the bevel portion and the edge portion.

The substrate peripheral portion measuring device of the inventionpreferably comprises a passage forming portion enclosing the peripheralportion for forming a passage to feed the liquid onto the peripheralportion, and the wave transmitting/receiving portion of the wavetransceiver is arranged in the passage. By thus providing the passageforming portion, the liquid flow at the peripheral portion can bestabilized to improve the measuring ability.

The wall face of the passage preferably has a wave collecting faceshaped to further reflect the reflected wave thereby to collect thereflected wave, and the wave transceiver has a portion at a position,where the reflected wave is collected, for receiving the reflected wave.This configuration causes the wall face of the passage not only to guidethe liquid but also to function as the wave collecting face forcollecting the reflected waves. As a result, the wave transceiver canreceive the reflected light properly thereby to improve the measuringability.

The device of the invention preferably comprises a liquid removing unitfor blowing away the liquid from the peripheral portion, and the wavetransceiver transmits the transmission wave to the place where theliquid is blown away by the liquid removing unit. By thus providing theliquid removing unit, the influences of the liquid can be reduced toimprove the measurement precision.

The device of the invention preferably comprises a liquid blocking unitenveloping the peripheral portion partially for blocking the arrival ofthe liquid at the peripheral portion, and the wave transceiver isdisposed to transmit/receive the wave through the liquid blocking unit.By thus providing the liquid blocking unit, the influence of the liquidcan be reduced to improve the measurement precision.

In the invention, the reflected wave processing unit may decide thestate of the peripheral portion on the basis of the relative change ofthe reflected wave accompanying the change of the substrate. Thereflected wave processing unit may decide the state of the peripheralportion on the basis of the time differentiation of the reflected waveaccompanying the change of the substrate. The reflected wave processingunit may decide the state of the peripheral portion by performing afrequency analysis of the reflected wave.

In the invention, moreover, the reflected wave processing unit mayperform an end point detection of the processing of the peripheralportion. The reflected wave processing unit may monitor the state of thetreating procedure of the peripheral portion. The reflected waveprocessing unit may detect a defect of the peripheral portion. Here inthe invention, the peripheral portion treatment includes a polishingtreatment and an etching treatment. More specifically, the peripheralportion treatment includes a bevel polishing, an edge polishing, a beveletching and an edge etching. One treatment may be carried out, and aplurality of treatments may also be carried out.

In the invention, moreover, the wave transceiver may transmit at leastone of a laser light, a while light, a microwave, an ultrasonic wave andan alternating magnetic field signal as a transmission wave to theperipheral portion. The typical transmission wave is the laser light.

Moreover, a plurality of the wave transceivers may be arranged along theperipheral portion of the substrate. Moreover, the substrate peripheralportion to be measured may have a silicon nitride film, a silicon oxidefilm, a poly-silicon film, a barrier film of Ta, TaN, TiN, Ti or thelike, or a metal film of Cu, W or the like.

Preferably, the reflected wave processing unit has means for clearingthe signal of the reflected wave of noise components. By thus removingthe noise components, the signal indicating the state of the peripheralportion can be obtained precisely and stably.

Preferably, the wave transceiver is configured to project a laser lightand to receive a reflected light; and a beam size is set according tothe movement of the turning wafer. By thus setting the beam sizeaccording to the wafer movement, the state of the peripheral portion ofthe wafer can be precisely measured even if the turning wafer moves tosome extent.

Preferably, the device of the invention comprises: a modulation unit formodulating the laser light projected as the transmission wave by thewave transceiver; and a synchronism detecting unit for detecting thereflected light received as the reflected wave by the wave transceiver,in synchronism with the modulation by the modulation unit. By thusperforming the modulation of the laser light and the synchronousdetection of the reflected light, the measurement sensitivity can beaugmented to improve the measuring ability.

Preferably, the wave transceiver is configured to send a plurality ofkinds of transmission waves, and the signal processing unit isconfigured to process a plurality of kinds of reflected waves receivedby the wave transceiver. Here, a plurality of kinds of the transmissionwaves are those of at least two kinds of the aforementioned laser light,white light, microwave, ultrasonic wave and alternating magnetic fieldsignal. The kind of transmission wave to be used for the measurement ischanged according to the material of the substrate peripheral portion tobe measured. Moreover, the kind of transmission wave may be changed asthe substrate treatment such as the polish advances. By thus selectivelyusing the plurality of kinds of transmission waves, the propertransmission waves can be used to improve the measuring ability.

Preferably, the reflected wave processing unit decides the state of theperipheral portion on the basis of zone data obtained from reflectedwaves of measurement zones disposed along the outer circumference of thesubstrate. Here, the zone data represent the reflected waves of themeasurement zones and are an average of the amplitudes of the reflectedwaves obtained from a plurality of measurement zones. By using the zonedata, the state of the substrate peripheral portion can be properlygrasped to improve the measuring ability.

Preferably, the reflected wave processing unit decides the state of theperipheral portion by comparing the zone data obtained from themeasurement zones. By thus comparing the zone data of the measurementzones, the situation of the peripheral portion can be grasped withreference to the measurement zones. As a result, the state of thesubstrate peripheral portion can be properly grasped to improve themeasuring ability.

Preferably, the reflected wave processing unit decides the state of theperipheral portion on the basis of the reflection according to thematerial change of the surface of the peripheral portion accompanyingthe treatment of the substrate. By thus noting the change of thereflection according to the material change of the surface of theperipheral portion, the state of the peripheral portion can be preciselydecided to improve the measuring ability.

Preferably, the reflected wave processing unit decides the state of theperipheral portion on the basis of the change of the pattern change ofthe reflected wave according to the material change of the surface ofthe peripheral portion accompanying the treatment of the substrate. Bythus noting the change of the reflection pattern according to thematerial change of the surface of the peripheral portion, the state ofthe peripheral portion can be precisely decided to improve the measuringability.

Moreover, the measuring device of the invention may belong to asubstrate peripheral portion polishing apparatus for polishing theperipheral portion of a substrate, and may measure the polished state ofthe peripheral portion of the substrate being polished. Moreover, themeasuring device may belong to a substrate treating apparatus providedwith a substrate peripheral portion polishing apparatus for polishingthe peripheral portion of a substrate, and may measure the polishedstate of the peripheral portion of the substrate being polished.

Moreover, the measuring device may belong to a substrate rinsingapparatus, and may measure the polished state of the peripheral portionof the substrate being rinsed. Moreover, the measuring device may belongto substrate treating apparatus provided with a substrate rinsingapparatus, and may measure the polished state of the peripheral portionof the substrate being rinsed.

According to another aspect of the invention, there is provided asubstrate peripheral portion polishing apparatus which comprises: asubstrate holder for holding a substrate; a substrate turning unit forturning the substrate; a liquid supply unit for supplying the substratewith a liquid; an peripheral portion polishing unit for polishing theperipheral portion of the substrate while being supplied with theliquid; a wave transceiver for transmitting a transmission wave to theperipheral portion while the liquid is flowing on the peripheralportion, and for receiving a reflected wave from the peripheral portion;a received wave processing unit for processing the signal of thereflected wave to decide the polished state of the peripheral portion;and a control unit for controlling the polish of the peripheral portionin accordance with the polished state of the peripheral portion obtainedby the received wave processing unit. Thus, the invention can measurethe peripheral portion properly even in the situation where the liquidflows on the peripheral portion. Therefore, the invention can measurethe state of the peripheral portion being polished.

Preferably, the substrate peripheral portion polishing apparatuscomprises a passage forming portion enclosing the peripheral portion forforming a passage to feed the liquid onto the peripheral portion, andthe wave transmitting/receiving portion of the wave transceiver isarranged in the passage. By thus providing the passage forming portion,the flow of the liquid on the peripheral portion can be stabilized toimprove the measuring ability.

Preferably, the wall face of the passage has a wave collecting faceshaped to further reflect the reflected wave thereby to collect thereflected wave and the wave transceiver has a portion at a position,where the reflected wave is collected, for receiving the reflected wave.This configuration causes the wall face of the passage not only to guidethe liquid but also to function as the wave collecting face forcollecting the reflected waves. As a result, the quantity of thereflected waves received by the wave transceiver can be augmented toimprove the measuring ability.

Preferably, the apparatus comprises a liquid removing unit for blowingaway the liquid from the peripheral portion, and the wave transceivertransmits the transmission wave to the place where the liquid is blownaway by the liquid removing unit. By thus providing the liquid removingunit, the influence of the liquid can be reduced to improve themeasurement precision.

Preferably, the apparatus comprises a liquid blocking unit envelopingthe peripheral portion partially for blocking the arrival of the liquidat the peripheral portion, and the wave transceiver is disposed totransmit/receive the wave through the liquid blocking unit. By thusproviding the liquid blocking unit, the influence of the liquid can bereduced to improve the measurement precision.

In the apparatus, the received wave processing unit may detect thepolish end point of the peripheral portion, and the control unit may endthe polish of the peripheral portion when the polish end point of theperipheral portion is detected. Moreover, the received wave processingunit may monitor the state of the polishing procedure of the peripheralportion, and the control unit may control the polishing condition of theperipheral portion in accordance with the state of the polishingprocedure of the peripheral portion. The control unit may control atleast one of the turning speed of the substrate, the pushing force ofthe polishing tool to the peripheral portion, the feed movement of thepolishing tape, the feed speed of the polishing tape, the relativemovement of the polishing head with respect to the substrate, therelative moving speed of the polishing head with respect to thesubstrate, and the feed rate of the liquid. The polishing condition canbe effectively changed by controlling at least one of the turning speedof the substrate, the pushing force of the polishing tool to theperipheral portion, the feed movement of the polishing tape, the feedspeed of the polishing tape, the relative movement of the polishing headwith respect to the substrate, the relative moving speed of thepolishing head with respect to the substrate, and the feed rate of theliquid. Moreover, the received wave processing unit may decide whetheror not the peripheral portion is defective.

Preferably, the apparatus comprises an abnormality detecting unit fordetecting that a polish abnormality has occurred when the polish endpoint is not detected even if the polishing time reaches a predeterminedmaximum polishing time, and the control unit stops the polish when theabnormality is detected by the abnormality detecting unit. As a result,the apparatus can cope with the polish abnormality properly.

Preferably, the apparatus comprises an abnormality detecting unit fordetecting that a polish abnormality has occurred when the waveform ofthe reflected wave is abnormal, and the control unit stops the polishwhen the abnormality is detected by the abnormality detecting unit. As aresult, it is possible to cope with the polish abnormality properly.

Preferably, the apparatus comprises a tool exchange informing unit forinforming the arrival of an exchanging timing of a polishing tool whenthe polishing rate obtained from the reflected wave lowers to apredetermined tool exchanging threshold rate. As a result, theexchanging timing can be properly informed to promote the exchange at aproper timing.

Preferably, the wave transceiver is configured to send a plurality ofkinds of transmission waves, and the kind of the transmission wave to beused for the measurement is changed according to the proceedingsituation of the polishing procedure determined from the reflected wave.Here, the plurality of kinds of transmission waves are those of at leasttwo kinds of the aforementioned laser light, white light, microwave,ultrasonic wave and alternating magnetic field signal. By thusselectively using the plurality of kinds of transmission waves, theproper transmission waves can be used to improve the measuring ability.

Preferably, the wave transceiver is configured to send a plurality ofkinds of transmission waves, and the kind of the transmission wave to beused for the measurement is changed in association with the change ofthe polishing condition by the control unit. By thus changing the kindsof transmission waves according to the polishing condition, the propertransmission waves can be used to improve the measuring ability.

Preferably, the control unit controls the polish of the substrate on thebasis of the polishing state and the control parameter of a peripheralportion polishing tool. Here, the control parameter is exemplified bythe torque current of the control motor of the polishing tape. By thusutilizing the control parameter, the polish control can be properlymade.

Preferably, the control unit interchanges the control based on thecontrol parameter and the control based on the polishing state, inaccordance with the progress of the polishing procedure of thesubstrate. For example, a coarse control is made in the first half ofthe polish on the basis of the control parameter, and a fine control ismade in the second half of the polish by using the reflected wave. Thus,the polish control can be made by using the control parameter properly.

Preferably, the received wave processing unit detects the polish endpoint by comparing the polish end point target set according to thereflected wave at an initial polishing stage and the reflected waveobtained from the wave transceiver. By setting the polish end pointtarget, the polish end point can be properly detected.

Preferably, the apparatus comprises an end time setting unit for settingthe polish end time, at which the polish end point is reached, on thebasis of a reference time till a predetermined reference polishing stateis obtained in the polishing procedure. As a result, the polishing timecan be precisely set by using the information on the polishing stateobtained by the measurement during the polish.

According to another aspect of the invention, there is provided asubstrate rinsing apparatus, which comprises: a substrate holder forholding a substrate; a substrate turning unit for turning the substrate;a liquid supply unit for supplying the substrate with a liquid; a wavetransceiver for transmitting a transmission wave to the peripheralportion of the substrate while the liquid is flowing on the peripheralportion, and for receiving a reflected wave from the peripheral portion;and a received wave processing unit for processing the signal of thereflected wave to decide the polished state of the peripheral portion.Thus, the aspect of the substrate rinsing apparatus can also achieve theadvantages of the invention.

According to another aspect of the invention, there is provided asubstrate peripheral portion measuring method for measuring the state ofthe peripheral portion of a substrate. In this method: a transmissionwave is transmitted to the peripheral portion while a liquid is beingfed to the substrate and is flowing on the peripheral portion; areflected wave is received from the peripheral portion; and the signalof the reflected wave is processed to decide the state of the peripheralportion. Thus, the mode of the substrate peripheral portion measuringdevice can also achieve the advantages of the invention.

According to another aspect of the invention, there is provided asubstrate peripheral portion polishing method. In this method: asubstrate is held; the substrate is turned; the substrate is suppliedwith a liquid; the peripheral portion of the substrate is polished whilethe liquid is being supplied; a transmission wave is transmitted to theperipheral portion while the liquid is flowing on the peripheralportion; a reflected wave is received from the peripheral portion; thesignal of the reflected wave is processed to decide the polished stateof the peripheral portion; and the polish of the peripheral portion iscontrolled in accordance with the polished state of the peripheralportion.

According to another aspect of the invention, there is provided asubstrate peripheral portion rinsing method. In this method: a substrateis held; the substrate is turned; the substrate is supplied with aliquid; a transmission wave is transmitted to the peripheral portion ofthe substrate while the liquid is flowing on the peripheral portion; areflected wave is received from the peripheral portion; and the signalof the reflected wave is processed to decide the polished state of theperipheral portion.

According to the invention, as has been described hereinbefore, theperipheral portion can be properly measured even in the situation wherethe liquid flows at the peripheral portion. For example, the peripheralportion can be properly measured midway of the polish of the peripheralportion of the wafer substrate. By measuring the peripheral portionduring the polish, the visual inspection and the polishing time settingwork of the prior art can be eliminated to improve the productivity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a substrate peripheral portion polishingapparatus of an embodiment.

FIG. 1A is a sectional view of a peripheral portion of a straight typewafer.

FIG. 1B is a sectional view of a peripheral portion of a round typewafer.

FIG. 2 is a diagram showing an example of flaws of an object to bepolished.

FIG. 3 is a diagram showing a projecting/receiving unit of the substrateperipheral portion measuring device.

FIG. 4 is a diagram showing a substrate peripheral portion measuringdevice of another embodiment.

FIG. 5 is a diagram showing a substrate peripheral portion measuringdevice of another embodiment.

FIG. 6 is a diagram showing a substrate peripheral portion measuringdevice of another embodiment.

FIG. 7 is a diagram showing a substrate peripheral portion measuringdevice of another embodiment.

FIG. 8 is a diagram showing a substrate peripheral portion measuringdevice of another embodiment.

FIG. 9 is a diagram showing a substrate peripheral portion measuringdevice of another embodiment.

FIG. 10 is a diagram showing a substrate peripheral portion measuringdevice of another embodiment.

FIG. 11 is a diagram showing a measuring process based on the effectiveamplitude of a reflected light.

FIG. 11A is a diagram showing a measuring process based on the effectiveamplitude of a reflected light.

FIG. 12 is a diagram showing a measuring process based on the frequencyanalyzing result of a reflected light.

FIG. 13 is a diagram showing a configuration of the case, in which alaser light is modulated.

FIG. 14 is a diagram showing a control process of a polishing condition.

FIG. 15 is a diagram showing a configuration of the case, in which aplurality of kinds of transmission waves are utilized.

FIG. 16 is a diagram showing measurement zones for a zone treatment.

FIG. 17 is a diagram showing a change in the pattern of a reflectedlight.

FIG. 18 is a diagram showing a substrate treating apparatus which isprovided with the substrate peripheral portion polishing apparatus.

FIG. 19 is a diagram showing a plating substrate treating apparatus,which is provided with a rinsing apparatus.

FIG. 20 is a diagram showing the rinsing apparatus.

FIG. 21 is a diagram showing a CMP substrate treating apparatus, whichis provided with the rinsing apparatus.

FIG. 22 is a diagram showing plating substrate treating apparatus, whichis provided with the rinsing apparatus.

FIG. 23 is a diagram showing the measured data of an unpolished product.

FIG. 24 is a diagram showing the measured data of a polished product.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings.The following detailed description and the accompanying drawings do notlimit the invention. Instead, the scope of the invention is defined bythe appended claims.

In the present embodiment, a substrate peripheral portion measuringdevice belongs to a substrate peripheral portion polishing apparatus forpolishing the peripheral portion of a semiconductor wafer.

In FIG. 1, a substrate peripheral portion polishing apparatus 10 isprovided with a turnable substrate holder 12. A wafer 14 is held on thesubstrate holder 12. The spindle 16 of the substrate holder 12 isconnected to a motor 18. When this motor 18 rotates, the wafer 14 turnswith the substrate holder 12. Above the substrate holder 12, there isdisposed a nozzle 20. This nozzle 20 is connected through a controlvalve 22 to a water tank 24.

As a component for polishing the peripheral portion 30 of the wafer 14,there is disposed a polishing tape 32. This polishing tape 32 is apolishing tool having a polishing material adhered to the tape. Thispolishing tape 32 is arranged to contact with the wafer peripheralportion 30. The polishing tape 32 is backed by a pad 34, which is pushedby an actuator 36. This actuator 36 pushes the pad 34 and then thepolishing tape 32 onto the peripheral portion 30 of the wafer 14. Theactuator 36 is constructed of a cylinder.

Here in this embodiment, the peripheral portion of the substrateincludes a bevel portion and an edge portion. The bevel portion is theouter circumference of the substrate. The edge portion is the two sideportions of the bevel portion (i.e., the end portions of the surface andthe back).

FIG. 1A and FIG. 1B are enlarged sectional views of the portions of theperipheral portions of a wafer. FIG. 1A presents a sectional view of theso-called “straight type” wafer W having a peripheral portion composedof a plurality of straight portions. FIG. 1B presents a sectional viewof the so-called “round type” wafer W having a peripheral portioncomposed of a curved portion. In the following description, the bevelportion of the wafer W of FIG. 1A indicates the portion B. This portionB is composed of upper and lower slopes P and Q sloped from the upperface and lower face of the outer circumference of the wafer W, and aside face portion R of the outer circumference of the wafer W. In thewafer W of FIG. 1B, on the other hand, the bevel portion B of the waferindicates the portion where the section of the outer circumference ofthe wafer W has a curvature. Moreover, the edge portion of the waferindicates the portion of an area E of FIG. 1A and FIG. 1B. This area Eis defined by the boundary of the inner side of the bevel portion B ofthe wafer W and by an upper face D of the wafer W, in which thesemiconductor device is to be formed.

In the following description, the peripheral portion of the wafer Wincludes the bevel portion B and the edge portion E thus specified. Inthis embodiment, the bevel portion and/or the edge portion may bepolished. In the peripheral portion measurement to be describedhereinafter, too, the bevel portion and/or the edge portion may also bemeasured. Here, mainly, the configuration for polishing and measuringthe bevel portion is described by way of example.

In this embodiment, the peripheral portion is polished, and thisperipheral portion polishing is one peripheral portion treating example.The peripheral portion treatment includes etching. More specifically,the peripheral portion treatment includes a bevel polishing, an edgepolishing, a bevel etching and an edge etching. Here is described thepolishing treatment.

Reverting to FIG. 1, a polish controller 40 is a computer forcontrolling the aforementioned substrate peripheral portion polishingapparatus 10 as a whole. The polish controller 40 is configured tocontrol the motor 18, the control valve 22 and the actuator 36.

In the entire peripheral portion polishing actions, the polishcontroller 40 controls the motor 18 to turn the substrate holder 12together with the wafer 14. Moreover, the polish controller 40 opens thecontrol valve 22 to feed the (pure) water of the water tank 24 to theupper face of the wafer 14 through the nozzle 20. The water spreads onthe upper face of the wafer 14 and flows to the peripheral portion 30,from which it drops. In this state, the polish controller 40 controlsthe actuator 36 to push the polishing tape 32 to the peripheral portion30 of the wafer 14. As a result, the polishing tape 32 polishes theperipheral portion 30.

In FIG. 1, the nozzle 20 is located at the center portion of the wafer14 and is directed just below. However, the position and angle of thenozzle 20 are not limited to those of FIG. 1. The nozzle 20 may also bedisposed above the wafer periphery within such a range as can feed waternecessary for the polish, for example. Alternatively, the nozzle 20 maybe inclined with respect to the wafer 14. Then, the water may also beinjected at an angle with respect to the wafer 14.

On the other hand, FIG. 2 shows an example of flaws of the peripheralportion to be removed in the peripheral portion polishing treatment. InFIG. 2, for example, a wafer of 200 mm has an entire length of a waferouter circumference of 628 mm. Moreover, the wafer has a flaw height (inthe direction of the wafer thickness) of 10 to 250 microns, a length (inthe wafer circumference direction) of 10 microns to 628 mm (or theentire length) and a flaw depth of 10 to 50 microns. These flaws areremoved by the peripheral portion polishing treatment.

In the peripheral portion polishing treatment, on the other hand, thesubstrate peripheral portion may have a silicon nitride film, a siliconoxide film (SiO₂ (i.e., an oxide film)), a poly-silicon film, a barrierfilm of Ta, TaN, TiN, Ti or the like, or a metal film of Cu, W or thelike. These films are subjected to the following peripheral portionmeasurement. By removing these films, it is made possible to reduce theadverse affections of the remainder of the film effectively.

Here is described a substrate peripheral portion measuring device 50which belongs to the substrate peripheral portion polishing apparatus10. The substrate peripheral portion measuring device 50 is providedwith a projecting/receiving unit 52 and a signal processing controller54. The projecting/receiving unit 52 is provided with a projector 56 anda receiver 58. The projector 56 projects a laser light to the peripheralportion 30 of the wafer 14. The receiver 58 receives the reflected lightfrom the peripheral portion 30. The projection and reception areperformed through the film of the water flowing from the peripheralportion 30.

FIG. 3 shows a configuration of the projecting/receiving unit 52. InFIG. 3, an LD stabilizing light source device 70 (as will be named thelight source device 70) configures the projector, and a high-speedconverter 72 (as will be named the converter 72) configures thereceiver. A projecting optical fiber 74 is attached to the light sourcedevice 70. A receiving optical fiber 76 is attached to the converter 72.The leading ends of the projecting optical fiber 74 and the converter 72are held in a sensor head 78. The laser light emitted from the lightsource device 70 passes through the projecting optical fiber 74 and isprojected to the wafer 14 through the lens of the sensor head 78. Thereflected light from the wafer 14 is received by the receiving opticalfiber 76, and reaches the converter 72 through the receiving opticalfiber 76. In the converter 72, the optical signal is converted into anelectric signal.

Reverting to FIG. 1, the receiver 58 converts the reflected light intothe electric signal, as described above, and feeds the electric signalto the signal processing controller 54. This signal processingcontroller 54 is a computer device, and converts the analog signal ofthe reflected signal into a digital signal. Moreover, the signalprocessing controller 54 processes the signal of the reflected light todecide the state of the peripheral portion 30 of the wafer 14. Theprocessed result of the signal processing controller 54 is displayed ina monitor 60 and fed to the polish controller 40.

The signal processing controller 54 may also decide the state of theperipheral portion 30 from the relative change of the effectiveamplitude of the reflected light. The signal processing controller 54may further decide the state of the peripheral portion 30 from thetime-differential value of the effective amplitude of the reflectedlight. The signal processing controller 54 may further decide the stateof the peripheral portion 30 from the frequency analysis result of theeffective amplitude by the FFT analysis. These parameters may beemployed in combination.

Moreover, the signal processing controller 54 determines the proceedingsituation of the polishing procedure as the state of the peripheralportion 30, and detects a polish end point. At this polish end point, adefect or the like of the peripheral portion 30 is polished away, andthe polish should be ended. The signal processing controller 54 may alsodetect a minute defect in the peripheral portion.

The processed result of the signal processing controller 54 is fed tothe polish controller 40, as described above. This polish controller 40controls the polish on the basis of the state of the peripheral portion30, which is determined by the signal processing controller 54. In thiscontrol, the polish controller 40 controls a polishing condition. Thepolishing condition is a motor speed, a water feed rate or a polishingtape pushing force. Another polishing condition is a feed of thepolishing tape, a feeding speed of the polishing tape, a relativemovement of the polishing head with respect to the wafer, or a movingspeed of the polishing head relative to the wafer. These parameters mayalso be controlled. The polishing rate is adjusted by the control of thepolishing condition.

When the signal processing controller 54 transmits the detection of thepolish end point to the polish controller 40, this polish controller 40ends the polish. Then, the actuator 36 is controlled so that thepolishing tape 32 is brought away from the peripheral portion 30 of thewafer 14. The motor 18 is stopped to stop the rotation of the wafer 14.

[Modifications]

The substrate peripheral portion polishing apparatus 10 and thesubstrate peripheral portion measuring device 50 of one embodiment ofthe invention have been described hereinbefore. In this embodiment, thewafer is fed with water. However, the wafer may also be fed with aliquid other than water.

The liquid may be any if it reduces the friction between the polishingtape and the wafer at the polishing time and the heat generation.Alternatively, the liquid or water may be mixed with polishing particlesfor aiding the polishing ability of the polishing tape. Likewise, theliquid may also be chemicals for aiding in the tape polish either byremoving the object by a chemical reaction or by facilitating removal ofthat.

In the embodiment, on the other hand, the laser light is projected.However, a transmission wave other than the laser light may also besent. However, a transmission wave other than the laser light may besent. For example, a white light (of halogen or xenon), a microwave, anultrasonic wave or an alternating magnetic field signal may betransmitted as the transmission wave. In the case of the halogen whitelight, the reflected light is condensed for spectroscopic analyses. Inthe case of the microwave, the reflected light is converted into asignal deflected from the incident signal thereof so that the deflectedsignal is analyzed. In the type of applying the alternating magneticfield, the reflected magnetic flux from the applied signal is convertedinto the impedance of an eddy-current sensor so that the convertedsignal is processed for analyses. In the case of using the microwave, onthe other hand, the embodiment is provided with a microwave waveguide.In the case of using the ultrasonic wave, the embodiment is providedwith an ultrasonic coaxial cable. In addition, a suitable configurationfor wave projections/receptions and for signal processing may also beprovided according to the kind of the transmission wave.

In the embodiment, on the other hand, the projecting/receiving unit isdisposed at one position on the circumference of the wafer 14. However,the projecting/receiving unit may also be disposed at a plurality ofpositions. In this case, the state of the peripheral portion 30 isdetermined with the reflected waves obtained from those positions sothat the peripheral portion polish is controlled.

In this embodiment, on the other hand, the sensor head is arrangedtransversely (with reference to the substrate face) of the wafer 14 sothat the projections/receptions are carried out in the transversedirection. On the other hand, the projections/receptions may also becarried out obliquely downward, obliquely upward, downward or upward.Moreover, the projections/receptions may also be carried out in aplurality of directions. For example, the projections/receptions mayfurther be carried out in three directions, obliquely downward,transversely and obliquely upward. The bevel portion and the edgeportions above and below the bevel portions can be measuredindependently of one another.

Here, the aforementioned various modifications can be likewise appliedeven to the following other embodiments.

In addition, the signal of the reflected light disperses due to thedevice difference of the projecting/receiving unit, although notexplained in the foregoing description. In order to avoid the influenceof the dispersion on the measurements, digital amplifications,offsetting and phase processing are properly executed on the sensorhardware unit and its controller. This execution can reduce theinfluence of the device difference and can improve the measuringprecision.

[Passage Formations]

FIG. 4 and FIG. 5 show other configuration examples of the substrateperipheral portion measuring device. As shown, a substrate peripheralportion measuring device 80 is provided with a passage forming member 82in addition to the aforementioned configuration. This passage formingmember 82 has a U-shaped sectional shape. The passage forming member 82encloses the peripheral portion 30 of the wafer 14 to form a passage 84for feeding water into the peripheral portion 30. Moreover, the passageforming member 82 is disposed at a portion of the entire wafercircumference. The water is fed from the nozzle 22 to the wafer 14 andflows on the upper face of the wafer 14 and into the passage 84. Thewater then reaches the peripheral portion 30 in the passage 84 and flowsover the peripheral portion 30 and out of the passage 84.

In this embodiment, moreover, the projecting/receiving portions of theprojecting/receiving unit 52 are arranged in the passage 84, as shown.More specifically, the (not-shown) sensor head of theprojecting/receiving unit 52 is attached to the passage forming member82. Moreover, the projecting optical fiber and the receiving opticalfiber are arranged in a measurement hole 88 formed in the wall face 86of the passage forming member 82. As a result, the projecting/receivingunit 52 projects the laser light through the water in the passage 84 andreceives the reflected light.

Thus in the embodiment, the flow of the liquid at the peripheral portioncan be stabilized by providing the passage forming portion. Moreover,the projections/receptions are carried out through the stable flow sothat the influence of the flow on the projected/reflected light can bereduced to improve the measuring ability.

[Condensation Face]

FIG. 6 shows another configuration example of the substrate peripheralportion measuring device. Like the configurations of FIG. 4 and FIG. 5,the substrate peripheral portion measuring device 90 of this embodimentis provided with a passage forming member 92. In this embodiment,moreover, the wall face 96 of the passage 94 of the passage formingmember 92 is made of a material for reflecting the laser light. Forexample, the passage forming member 92 is made of iron or glass havingalumina vapor-deposited thereon. As a result, the laser light isreflected on the wall face 96. Moreover, this wall face 96 is made of awave-collecting face shaped to reflect and collect the reflected light.

More specifically, the peripheral portion 30 of the wafer 14 is composedof a bevel portion 30 a and upper and lower corner portions 30 b and 30c. The laser light is horizontally projected to the wafer 14. Thereflected light of the bevel portion 30 a is reflected in a horizontaldirection. On the contrary, the reflected light of the upper cornerportion 30 b proceeds upward and is reflected again on the upper sideportion of the wall face 96 so that it is collected downward. On theother hand, the reflected light of the lower corner portion 30 cproceeds downward and is reflected again on the lower side portion ofthe wall face 96 so that it is collected upward.

In this embodiment, as shown, the receiving portion of the reflectedlight is disposed at the position where the reflected light is collectedby the wall face 96. Specifically, the receiving optical fibers arearranged in measuring holes 98 in the upper side portion, the centerportion and the lower side portion of the wall face 96. These receivingoptical fibers receive the individual reflected lights of the lowercorner portion 30 c, the bevel portion 30 a and the upper corner portion30 b.

Thus, in this embodiment, the passage wall face functions not only toguide the liquid but also as the wave collecting face for collecting thereflected wave. As a result, it is possible to collect the reflectedlight efficiently.

Here in this embodiment, the condensation may be made within a range sowide as is necessary for satisfying the demand for the measuringability. The light need not be precisely collected at one point unlikethe imaging optical system. Moreover, the condensing unit of the wallface may be a suitable curved face such as a semicircle or semi-ellipse.

[Water Eliminating Configuration]

FIG. 7 and FIG. 8 show another configuration example of the substrateperipheral portion measuring device. As shown, the substrate peripheralportion measuring device 100 is provided with a water removing nozzle102. This water removing nozzle 102 is arranged in the vicinity of theperipheral portion 30 of the wafer 14. The water removing nozzle 102injects air toward the peripheral portion of the wafer 14 so that itblows of f and eliminates the water of the peripheral portion 30locally.

As shown, the projecting/receiving unit 52 is arranged to project thelaser light to the place to be cleared of water. More specifically, thesensor head is arranged in the vicinity of the place to be cleared ofwater. The projecting optical fiber and the receiving optical fiberproject/receive the light to/from the place to be cleared of water.

Thus, this embodiment is provided with the liquid removing unit so thatit can reduce the influence of water on the measurements thereby toimprove the measuring precision.

Here, the gas to be injected by the water removing nozzle 102 is notlimited to air. Specifically, the water removing nozzle 102 may inject agas other than air, such as a nitrogen gas. The water removing nozzle102 may inject such a suitable gas, e.g., the nitrogen gas or an inertgas as will not raise the problem that the film on the wafer surface isoxidized or reduced.

[Water Blocking Configuration]

FIG. 9 and FIG. 10 show another configuration example of the substrateperipheral portion measuring device. As shown, the substrate peripheralportion measuring device 110 is provided with a water blocking pad 112.This water blocking pad 112 has a shape for enveloping the peripheralportion 30 of the wafer 14 partially. More specifically, the waterblocking pad 112 has a groove 114. The peripheral portion 30 is sofitted in the groove 114 as to closely contact with the inner face ofthe groove 114. The water blocking pad 112 is fixed. As the wafer 14turns, therefore, the peripheral portion 30 of the wafer 14 slides inthe groove 114.

The water blocking pad 112 is made of such a soft material as not todamage the wafer 14. The water blocking pad 112 is also made of such atransparent material as to transmit the laser light. For example, thewater blocking pad 112 is made of a transparent urethane material.

In this embodiment, on the other hand, the projecting/receiving unit 52is arranged to project/receive the light through the liquid blocking pad112. More specifically, the sensor head makes contact with the liquidblocking pad 112. The projecting optical fiber and the receiving opticalfiber are directed toward the peripheral portion 30 through the liquidblocking pad 112. The optical fibers may bite into the liquid blockingpad 112.

Thus, this embodiment is provided with the liquid blocking unit so thatit can reduce the influence of water on the measurements thereby toimprove the measuring precision.

[Signal Processing (Real Data)]

Next, the processing of the signal processing controller (54 in FIG. 1)is described in more detail. The signal processing controller convertsthe analog signal of the reflected light, when it receives the analogsignal from the projecting/receiving unit 52, into a digital signal. Thesignal processing controller processes the signal of the digital type ofthe reflected light to determine the effective amplitude. Moreover, thesignal processing controller determines the state of the peripheralportion 30 from the real data of the effective amplitude. For example,there is determined the relative change of the effective amplitude, fromwhich the proceeding situation of the polishing procedure is monitoredto detect the polish end point.

FIG. 11 shows the effective amplitude of the reflected signalschematically. At the polish start time, the amplitude largely changesin a portion on the circumference of the wafer. As the polish proceeds,the peak of the amplitude becomes lower. At the instant when the peak ofthe amplitude becomes equal to or lower than a predetermined thresholdvalue, the polish end point is detected.

In the example of FIG. 11, the amplitude becomes even as the polishproceeds. However, the amplitude may exhibit a reverse tendency. In thiscase, the dispersion of the amplitude grows large as the polishproceeds. The polish end point is detected when the dispersion reaches apredetermined threshold value.

FIG. 11A shows another example. In the example of FIG. 11A, theeffective amplitude becomes large as the polish proceeds. The polish endpoint is detected at the instant when the entire effective amplitudeexceeds the threshold value.

The processing of the real data is not limited to the aforementionedexamples. An arbitrary featuring event (or a characteristic detectedpattern) corresponding to the polish end point may be specified from thereal data so that the polish end point may be detected. The usablecharacteristic event is exemplified by: (1) a value no less than apredetermined value; (2) a value no more than a predetermined value; (3)a maximum; (4) a minimum; (5) a rise start point; (6) a rise end point;(7) a fall start point; (8) a fall end point; (9) a value within apredetermined gradient range; (10) a gradient maximum; or (11) agradient minimum. A suitable pattern may be used according to the kindof the wafer, the state of the wafer peripheral portion or a measurementtarget.

[Signal Processing (Time Differentiation)]

On the other hand, the signal processing controller may determine thetime differentiation of the effective amplitude thereby to determine thestate of the peripheral portion from the time differentiation. In thistime differentiation, the polishing situation is grasped from the timedifferentiation. For example, a pattern corresponding to a flaw ismonitored. The polish end point is detected when the flaw patterndisappears.

For the time differentiation, like the real data, the characteristicevent corresponding to the polish end time may be extracted from theactually obtained time-differentiated data so that the polish end pointmay be detected. The examples of the characteristic event are enumeratedabove.

Here, the time differentiation may be of a first degree, a second degreeor a more degree. Differentiations of a plurality of degrees may be usedtogether.

[Signal Processing (Frequency Analysis)]

The signal processing controller may also subject the effectiveamplitude to the FFT processing for the frequency analysis. In thiscase, the proceeding situation of the polishing procedure is monitoredfrom the frequency analysis result to detect the polish end point.

FIG. 12 shows one example of the frequency analysis resultschematically. In this example, the level of a frequency (e.g., aleft-hand peak) is kept as the polish proceeds, but the level of anotherfrequency (e.g., three right-hand peaks) lowers as the polish proceeds.Therefore, the polishing procedure is monitored on the basis of thelatter frequency. The polish end point is detected at the instant whenthe level of the noted frequency lowers to a predetermined thresholdlevel.

In the example of FIG. 12, the levels of some frequencies drop as thepolish proceeds. As the polish proceeds, on the contrary, the levels ofsome frequencies can rise. Moreover, the levels of all frequencies canalso rise. In these cases, the state of the peripheral portion can belikewise detected from the result of the frequency analysis.

[Signal Processing (Integration)]

On the other hand, the signal processing controller may also perform aprocessing to integrate the effective amplitude. In this case, thesignal processing controller integrates the signals of the reflectedwave, which are obtained along the wafer circumference as the waferturns. From the integration result, the polished state is determined,and the polish end point is detected. In this case, too, thecharacteristic event corresponding to the polish end point is extractedfrom the integration result.

[Signal Processing/Defect Detection]

In the foregoing various processing operations, the polishing procedureis monitored, and the polish end point is detected. In addition, thesignal processing controller may also detect a defect. Preferably, acharacteristic portion indicating a minute defect is extracted from thesignal of a reflected wave. The characteristic portion of the minutedefect may be extracted from any of the aforementioned real data, thetime differentiation, the frequency analysis result or the integrationresult. A signal indicating the defect occurrence is displayed in themonitor.

Preferably, the signal processing controller acquires the reference (orposition) of the wafer from the notch of the wafer, the orientation flatand the signal difference of the remaining portions. Moreover, thesignal processing controller acquires information on the turning angleof the wafer. This turning angle of the wafer may be acquired from theangle of rotation of the motor. Moreover, the signal processingcontroller determines the position of a defect on the basis of theturning angle of the wafer. The position of the defect is expressed bythat on the wafer circumference. The position of the defect is alsodisplayed as a portion of the defect information in the monitor.

[Signal Processing/Noise Elimination]

The signal processing controller is configured to eliminate noisecomponents from the signal of the reflected light. For example, thesignal processing controller determines the noise components by the FFTsignal analysis. In accordance with the noise components specified, thesignal processing controller sets the cut-off frequency of a noiseeliminating filter. The adjustment of the cut-off frequency is suitablymade in the setting of the recipe of a control unit. The filter isexemplified by an LPF (Low Pass Filter), a BPF (Band Pass Filter), anHPF (High Pass Filter) or a notch filter. Filters of a plurality ofkinds may also be used together. The filter may also be realized by ananalog circuit or by a digital processing.

By thus eliminating the noise components, it is possible to acquire thesignal indicating the state of the peripheral portion precisely andstably, to specify the state of the peripheral portion precisely and todetect the polish end point precisely.

[Setting of Beam Size]

Here in this embodiment, the beam size of the laser light is set in thefollowing manner. The wafer moves to some extent in the horizontaldirection and in the vertical direction while it is turning. In orderthat the detection sensitivity may not lower even with the movement ofthe wafer, the beam size is set according to the movement of the work.As a result, the laser light is converged within the moving range of thework. In other words, the laser light irradiates the peripheral portionof the work properly, even if the work moves within that moving range.The beam size is adjusted by the control for focusing the light source.

In case a minute defect is to be detected, for example, the beam size isset to 10 microns×1,000 microns. The figure of 10 microns is atransverse beam size, and the figure of 1,000 microns is a longitudinal(i.e., the direction of the wafer thickness) beam size. By applyingthese beam sizes, the defect can be detected even if the wafer moves upand down. Moreover, the transverse beam size is made small, the quantityof light increases to retain the sensitivity for detecting the minutedefect.

When the homogeneity of the surface of the wafer peripheral portion isto be measured, for example, the beam is made circular to have a beamdiameter of 1 to 2 mm. As a result, the measurement of the entireperipheral portion can be effectively made even if the wafer moves.Because of the homogeneity measurement, moreover, a sufficientperformance can be attained even for the large beam size.

Thus in this embodiment, the state of the peripheral portion of thewafer can be precisely measured by setting the beam size according tothe movement of the wafer, even if the wafer moves to some extent whileit is turning.

[Modulation of Laser Light]

In this embodiment, on the other hand, the laser light is properlymodulated, as described in the following.

With reference to FIG. 13, in this embodiment, a pulse modulation iscarried out in a laser light source 120. For example, a coherence lightsource is used, and a pulse modulation of 34 kHz is carried out(although not limited to 34 kHz). As a result, a pulsating laser lightis projected on the wafer. A photodiode 122 also receives a pulsatingreflected light. The photodiode 122 converts the reflected light into anelectric signal. This electric signal is fed to a synchronism detector124. This synchronism detector 124 is fed with information on themodulation from the laser light source 120. The synchronism detector 124subjects the signal of the reflected light to a synchronous detection.The synchronously detected signal is fed to the signal processingcontroller 54.

Thus, this embodiment modulates the laser light. The laser light ismodulated, and only the peripheral portion polishing signal is highlysensitively extracted while eliminating the remaining noise signals,thereby to raise the S/N ratio. As a result, the measurement sensitivitycan be augmented to improve the measuring ability.

[Polish Control]

Next, the polish control based on the measurement result of theperipheral portion is described in more detail. This control is made bythe polish controller (40 of FIG. 1).

The polish controller controls the substrate peripheral portionpolishing apparatus, when the polish end point is detected, to end thepolish, as has already been described. During the polish, the polishcontroller also controls the polishing actions of the substrateperipheral portion polishing apparatus in accordance with the peripheralportion measurement result. Here is carried out the closed loop control.

The object of the control is the wafer turning motor, the water feedingcontrol valve, and the polishing tape pushing actuator. The polishcontroller controls at least one of the turning speed of the wafer, thepushing force of the polishing tool to the peripheral portion, the feedmovement of the polishing tape, the feed speed of the polishing tape,the relative movement of the polishing head with respect to thesubstrate, the relative moving speed of the polishing head with respectto the wafer, and the feed rate of water. By this control, the polishingspeed (or the polishing rate) is adjusted. When the motor speed israised, for example, the polishing speed is raised. When the tapepushing force is raised, moreover, the polishing speed is raised. Thesefactors may be simultaneously controlled in association. Alternatively,the factors may also be controlled only partially.

FIG. 14 shows an example of a preferable polish control. It is assumedthat the peripheral portion polish is performed to expose the siliconfilm of the wafer to the outside and to smoothen the peripheral portionsurface. In FIG. 14, the abscissa indicates the time, and the ordinateindicates a parameter of the polishing state. This parameter isexemplified by the range (i.e., the difference between the maximum andthe minimum) of the effective amplitude of the reflected light.

The polish controller causes the polish in a high-speed mode till theparameter of the polishing state reaches a predetermined value P1.Specifically, the motor and so on are controlled so that the polishingspeed may take a predetermined high value. When the parameter reachesthe value P1 at a time t1, the polishing speed is switched to alow-speed mode for the polish. The motor and so on are controlled sothat the polishing speed may take a predetermined value lower than thehigh-speed mode. When the parameter of the polishing state reaches avalue P2 corresponding to the polish end point, the polish controllerends the polish. At this time, the peripheral portion of the wafer iscleared of the unnecessary film or the like so that the silicon faceappears with a smooth surface.

Thus, this embodiment can control the polish properly on the basis ofthe measured state of the peripheral portion. Moreover, the polishingcondition can be effectively changed by controlling at least one of theturning speed of the substrate, the pushing force of the polishing toolto the peripheral portion, the feed movement of the polishing tape, thefeed speed of the polishing tape, the relative movement of the polishinghead with respect to the substrate, the relative moving speed of thepolishing head with respect to the substrate, and the feed rate of aliquid. Moreover, the polishing speed can be raised within a properrange on the basis of the measurement result thereby to shorten thepolishing time period.

[Abnormality Detection (Excess of Polishing Time)]

Here is described an abnormality detecting function of this embodiment.This function is realized by the signal processing controller 54 ofFIG. 1. This signal processing controller 54 receives the information ofthe polish start from the polish controller 40, and monitors the lapsetime from the polish start. The signal processing controller 54 decideswhether or not a predetermined maximum polishing time period has elapsedfrom the polish start. This maximum polish time is preset and stored inthe signal processing controller 54.

In case the polish is being normally carried out, the polish end pointis detected before the maximum polishing time period elapses. In casethe polish end point is not detected even if the maximum polishing timeperiod elapses, it is deemed that some abnormality has occurred. Thisabnormality can be exemplified by a trouble in the polishing apparatusor in the measuring device.

The signal processing controller 54 decides that a polishing abnormalityhas occurred, if the polish end point is not detected even when thepolishing time period reached the maximum polishing time. The signalprocessing controller 54 sends a signal indicating the occurrence of anabnormality to the polish controller 40. This polish controller 40controls the motor and so on, when it receives the signal indicating theabnormality occurrence, to stop the polish forcibly. On the other hand,the signal processing controller displays the abnormality occurrence onthe monitor 60.

Thus, according to this embodiment, the polishing abnormality can beproperly coped with.

[Abnormality Detection (Abnormality Signal)]

Here is described another abnormality detecting function. In thisdetecting function, the signal processing controller 54 decides that thepolishing abnormality has occurred, if the signal waveform of thereflected light is abnormal. In this processing, the signal processingcontroller 54 is stored with the information indicating the standardstate of the signal waveform of the reflected light. The signalprocessing controller 54 decides whether or not the waveform of thereflected light obtained by the measurement has deviated from thestandard state. When the actual waveform deviates the standard state,the signal processing controller 54 decides that the abnormality hasoccurred.

The abnormality occurrence is displayed in the monitor 60 andtransmitted to the polish controller 40. This polish controller 40controls the motor and so on to stop the polish forcibly.

Thus, this embodiment can cope with the polishing abnormality properly.

Here have been described the abnormality detections of two kinds (i.e.,the abnormality detection due to the excess of the polishing timeperiod, and the abnormality detection due to the abnormal signal). Theseabnormality detections may be separately used according to the state ofthe wafer peripheral portion of the object to be measured. One ofabnormality detections may also be made according to the state of thewafer peripheral portion.

[Report of Timing for Tool Exchange]

Here is described a function to report the time for a tool exchange inthis embodiment. This function is realized by the signal processingcontroller 54. The signal processing controller 54 monitors thepolishing rate obtained from the information on the reflected wave.Here, the signal processing controller 54 receives the information onthe polish start from the polish controller 40. On the other hand, thesignal processing controller 54 detects the polish end point from thesignal of the reflected wave. Moreover, the signal processing controller54 calculates the polishing rate from the time period from the polishstart to the polish end point.

The signal processing controller 54 monitors the polishing rate thusobtained. The polishing rate lowers as a number of wafers are treated.The signal processing controller 54 reports the arrival of theexchanging time of the polishing tool, when the polishing rate drops toa predetermined tool exchanging threshold rate. Here, the signalprocessing controller 54 displays an image indicating the toolexchanging timing on the monitor 60.

Thus, according to this embodiment, the exchanging timing can beproperly reported to promote the exchange of the tool at a propertiming.

In this embodiment, the polishing time period may also be monitored.This polishing time period corresponds to the polishing rate so that thepolishing rate can also be monitored by monitoring the polishing timeperiod.

In case the polishing condition is adjusted by the polish controller, itis preferred to monitor the change in the polishing rate inconsideration of the polishing condition.

[Combination of Transmission Waves of a Plurality of Kinds]

Here is described a preferred configuration example for combiningtransmission waves of a plurality of kinds. In the description thus farmade, the transmission wave is mainly the laser light. In thisembodiment, on the contrary, the transmission waves of a plurality ofkinds are combined. One of these transmission waves may naturally be thelaser light.

FIG. 15 shows a substrate peripheral portion polishing apparatus of thisembodiment schematically. In the substrate peripheral portion polishingapparatus 130, a wave transceiver unit 132 is composed of a first wavetransceiver 132 a and a second wave transceiver 132 b. The first wavetransceiver 132 a performs the projection/reception of the firsttransmission wave, and the second wave transceiver 132 b performs thetransmission/reception of the second transmission wave. The firsttransmission wave and the second transmission wave are exemplified by alaser light, a white light, a microwave, an ultrasonic wave or analternating magnetic field signal. The first transmission wave and thesecond transmission wave are of different kinds. In case thetransmission wave is the laser light, the wave transceiver unit is theaforementioned projecting/receiving unit.

A signal processing controller 134 receives the electric signal of thefirst reflected wave corresponding to the first transmission wave, fromthe first wave transceiver 132 a, and processes the signal of the firstreflected wave to determine the state of the wafer peripheral portion.Moreover, the signal processing controller 134 receives the electricsignal of the second reflected wave corresponding to the secondtransmission wave, from the second wave transceiver 132 b, and processesthe signal of the second reflected wave to determine the state of thewafer peripheral portion.

The signal processing controller 134 controls the first wave transceiver132 a and the second wave transceiver 132 b to cause either of them toperform the wave transmission/reception. Moreover, the signal processingcontroller 134 processes the signal obtained from one of the first wavetransceiver 132 a and the second wave transceiver 132 b, to detect thestate of the peripheral portion. As a result, the first transmissionwave and the second transmission wave are selectively utilized.

The signal processing controller 134 may also cause both the first wavetransceiver 132 a and the second wave transceiver 132 b to perform thewave transmission/reception. Moreover, the signal processing controller134 may also determine the state of the wafer peripheral portion fromthe signal which is obtained from one of the first wave transceiver 132a and the second wave transceiver 132 b. In this case, too, the firsttransmission wave and the second transmission wave are selectivelyutilized.

Here is described the mode of switching the transmission wave to be usedfor the measurement. Here are described three preferred patterns.

(1) In the first pattern, the signal processing controller 134 changesthe kind of the transmission wave in accordance with the material of theperipheral portion of the wafer to be measured. As a result, thetransmission wave suited for the material of the peripheral portion canbe used to improve the measurement sensitivity and the measuringability.(2) In the second pattern, the signal processing controller 134 changesthe kind of the transmission wave to be used in the measurement, inaccordance with the proceeding situation of the polishing procedure. Theproceeding situation of the polishing procedure is obtained from thesignal of the reflected wave. In this embodiment, one transmission waveis used in the first half of the polish, and the other transmission waveis used in the second half of the polish.

When the polish is started, more specifically, one transmission wave isused to monitor the state of the wafer peripheral portion. When thewafer peripheral portion comes into a predetermined state, thetransmission wave to be used for the measurement is interchanged. Then,the state of the wafer peripheral portion is monitored with the othertransmission wave, and the polish end point is detected.

By thus changing the kind of the transmission wave in accordance withthe progress of the polish, the proper transmission wave can be used toimprove the measurement sensitivity and the measuring ability.

(3) In the third pattern, the signal processing controller 134 changesthe kind of the transmission wave in accordance with the polishingcondition. The information on the polishing condition is fed from thepolish controller 136 to the signal processing controller 134. Forexample, it is assumed that the high-speed mode and the low-speed modeare set as the polishing condition. The high-speed mode is set in thefirst half of the polish, and the low-speed mode is set in the secondhalf of the polish.

In this case, the signal processing controller 134 changes the kind ofthe transmission wave when the polishing condition changes. In amulti-step polish for which a plurality of polishing conditions are set,therefore, the transmission wave to be used for the measurement isinterchanged in association with the polishing condition.

In this embodiment, by thus changing the kind of the transmission wavein accordance with the polishing condition, a proper transmission wavecan be used to improve the measurement sensitivity and the measuringability.

In the foregoing description, the transmission waves of two kinds areused. On the contrary, it is natural that transmission waves of threekinds or more can be used. It is also natural that a plurality of wavetransceivers can be disposed for the transmission waves of theindividual kinds. In the foregoing description, the three patterns areexplained. Of these three, two or more patterns may also be suitablycombined.

[Joint Use of Peripheral Portion Measurement and Control Parameter ofPolishing Tool]

Here is described a proper embodiment, in which the peripheral portionmeasurement and the control parameter of the polishing tool are jointlyused. In the foregoing embodiment, as described with reference to FIG.1, the polishing tool is the polishing tape 32, which is pushed to thewafer 14 by the actuator 36, and this actuator 36 is made of thecylinder. In this embodiment, on the contrary, the actuator 36 isprovided with a control motor. In this case, the torque current of thecontrol motor can be used as the control parameter of the polishingtool. In this embodiment, moreover, the polish is controlled by usingthe torque current and the peripheral portion measurement result.

In this embodiment, more specifically, when the polish is started, thepolish controller 40 monitors the torque current. When the torquecurrent reaches a predetermined threshold value, the polish controller40 instructs the signal processing controller 54 of the start ofmeasurement. In accordance with this instruction, the signal processingcontroller 54 starts the measurement with the signal obtained from theprojecting/receiving unit 52. Moreover, the signal processing controller54 informs the polish controller 40 of the detection of the polish endpoint when it detects the polish end point. The polish controller 40controls the motor and so on to end the polish.

Thus, in this embodiment, the substrate polish is controlled on thebasis of the polishing state and the control parameter of the polishingtool, so that the polish can be properly controlled by using the controlparameter.

In this embodiment, on the other hand, the control based on the controlparameter and the control based on the polishing state are interchangedaccording to the progress of the substrate polishing procedure. In theaforementioned example, a coarse control is made in the first half ofthe polish on the basis of the control parameter, and a fine control ismade in the second half of the Polish by using the reflected wave. Thus,the polish control can be made by using the control parameter properly.

In this embodiment, too, transmission waves of a plurality of kinds maybe selectively used as in the foregoing embodiment. These transmissionwaves may also be used together with the control parameter of thepolishing tool.

[Zone Treatment]

Here is described a preferred embodiment for the zone treatment. Thiszone treatment is realized by a signal processing controller.

In the zone treatment, as referred to FIG. 16, a plurality ofmeasurement zones are provided along the outer circumference of thewafer when the signal of the laser reflected light is to be processed.In the shown example, the wafer outer circumference is divided into fivemeasurement zones. In the zone treatment, moreover, zone data aredetermined from the measurement zones. The zone data represent thesignals of reflected lights obtained from the measurement zones.Moreover, these zone data are used to determine the state of the waferperipheral portion.

In this embodiment, the wafer is turned, but the projecting/receivingunit is fixed. As the wafer is turned, therefore, the reflected light isobtained from the entire circumference of the wafer. The data of theentire zone are divided into the data of a plurality of zones.

The boundaries of the measurement zones may be either at arbitrarypositions on the wafer outer circumference or at preset positions. Inthis latter case, the signal processing controller acquires informationon the wafer turning angle thereby to determine the positions of theboundaries from the information on the wafer turning angle. Thereference of the wafer turning angle is exemplified by the positions ofnotches.

The zone data represent the signals of reflected lights obtained fromthe measurement zones, as described hereinbefore. The zone data areexemplified by the average value, the maximum, the level difference (orrange) and the like of the effective amplitudes of the reflected lightsin the measurement zones. Moreover, the zone data may be expressed bythe time differentiations of the effective amplitudes of the reflectedlights in the measurement zones, and the time differentiations may be ofa first degree, a second degree or more degrees.

The zone data of all measurement zones may be used for processing them.There may also be used the zone data of one or more predeterminedmeasurement zones. There may also be used the zone data of one or morearbitrarily selected measurement zones.

The zone data are compared with a preset designated value so that thepolish end point is detected. When the zone data come into apredetermined designated range, for example, the polish end point isdetected. The polish end point is also detected, when the zone databecome a predetermined designated value or higher. Alternatively, thepolish end point may also be detected when the zone data become apredetermined designated value or lower.

In the zone data processing, the following zone converging operation mayalso be preferably carried out. In the zone converging operation, thezone data of a plurality of measurement zones are compared.

In the zone converging operation, one measurement zone is designated. Itis then decided whether or not the difference in the zone data betweenthe designated zone and the remaining zones is at a predeterminedthreshold value or smaller. The polish end point is detected when thedifference in the zone data is at the threshold value or smaller. In thezone converging operation, the zone data may represent the effectiveamplitudes of the measurement zones or may be the time differentiation.

In this embodiment thus far described, the state of the substrateperipheral portion can be properly grasped by using the zone datathereby to improve the measuring ability.

By comparing the zone data of the measurement zones, moreover, thesituation of the peripheral portion can be grasped with reference to themeasurement zones so that the detection sensitivity of the state of theperipheral portion is improved. As a result, the state of the substrateperipheral portion can be properly grasped to improve the measuringability.

[Target Setting Operation]

In addition, the substrate peripheral portion measuring device of thisembodiment may also set the target of the polish end point thereby toperform the measurements with the set target, as described in thefollowing.

In this operation, the signal processing controller determines theremaining amount of polish from the signal of the reflected lightobtained at the initial stage of the polish, and sets the target of thepolish end point. This polish end point target indicates the reflectedlight, which is obtained when the polish of the remaining amount isended so that the wafer peripheral portion becomes smooth. The remainingamount of polish and the target of the polish end point are expressed bythe effective amplitude of the reflected light, for example.

The signal processing controller holds and uses the target of the polishend point to detect the polish end point. Here, the signal of thereflected wave inputted is compared with the target of the polish endpoint. This polish end point is detected when the input signal reachesthe target of the polish end point. The polish controller is informed ofthe polish end point to end the polish.

Thus, this embodiment can detect the polish end point properly bysetting the target of the polish end point.

[End time Setting Operation]

On the other hand, the substrate peripheral portion measuring device ofthis embodiment may also be configured to set the polish end time, asdescribed in the following.

In this operation, there is determined at first the reference time t1till the predetermined reference polished state is obtained in thepolishing procedure. An auxiliary time ta is calculated from thereference time t1 and a predetermined coefficient k1. For example,ta=t1×k1. The auxiliary time ta is calculated by ta=t1×k1, ta=t1/k1,ta=t1+k1, ta=t1−k1 and so on. The auxiliary time ta is a time periodfrom the reference time t1 to the polish end point. Therefore, a polishend time t2 (i.e., the time period from the polish START TIME to thepolish end time) is expressed by t1+ta. The additional polish is carriedfrom the reference time t1 to the polish end time t2.

The polish end time t2 is sent from the signal processing controller tothe polish controller so that it is applied for controlling the polishin the polish controller. In this embodiment, the polish end time t2 isproperly set by using a sample wafer. The polish end time t2 is held inthe polish controller and is applied, after the sample wafer isprocessed, for treating a plurality of wafers.

Thus, in this embodiment, the polishing time can be precisely set byusing the information on the polishing state obtained by themeasurements during the polish. Moreover, the polishing time can besimply set.

The target setting operation and the end time setting operation havethus far been described. Either the polishing ending target or thepolish end time may also be set depending on the material of the waferto be treated. Alternatively, operation may be carried out by using bothof them, and either setting time (i.e., an earlier time or a later time)may also be set as the end time, if necessary.

[Use of Relation Between Peripheral Portion Material and Reflection]

On the other hand, the substrate peripheral portion measuring device ofthis embodiment may also decide the state of the wafer peripheralportion on the basis of the change in the reflection according to thematerial change of the surface of the peripheral portion of the waferaccompanying the treatment of the wafer, as described in the followingexample.

Here, it is assumed that the silicon nitride (SiN) film of theperipheral portion of a silicon (Si) wafer is removed. Silicon andsilicon nitride are different in the absorption wavelengthcharacteristics as optical characteristics. The silicon nitride filmabsorbs a wavelength of 320 nm or less. On the contrary, the siliconwafer reflects the whole wavelength.

It is, therefore, set that the wavelength of the laser light is absorbedby the silicon nitride film. The wavelength of the laser light is set to240 to 320 nm, for example.

At the initial stage of the polish, the silicon nitride film exists onthe wafer surface so that the optical reflection is low. As the polishof the peripheral portion proceeds, the material of the wafer surfaceschanges from the silicon nitride into the silicon. When this siliconappears, the quantity of the reflected light abruptly rises. Thisoptical change is detected by the signal processing controller. Thepolish end point is detected when a predetermined optical changeappears. This optical change is so prominent that the end point isprecisely detected.

Thus, noting the change in the reflection according to the change in thematerial of the surface of the peripheral portion, the state of theperipheral portion can be precisely decided to improve the measuringability.

[Use of Relation Between Peripheral Portion Material and ReflectionPattern]

On the other hand, the substrate peripheral portion measuring device ofthis embodiment may also decide the state of the peripheral portion onthe basis of the change in the reflected pattern according to thematerial change of the surface of the peripheral portion accompanyingthe treatment of the wafer, as described in the following example.

When the output of the laser light is properly adjusted, a patternappears in the reflected light. In this embodiment, this reflectedpattern is used.

Here, it is assumed that the silicon nitride film (SiN) is removed fromthe peripheral portion of the silicon wafer (Si). As the polishproceeds, the silicon nitride film is removed to expose the siliconwafer to the outside.

With the irradiation of a collimated laser beam of a specificwavelength, as shown in FIG. 17, a significant difference appears in thereflected pattern between the silicon nitride film (unpolished) and thesilicon (polished). On the silicon nitride film, a fringe patternappears in the reflected pattern due to the diffraction of the filmedge. On the contrary, no fringe pattern appears in the reflectedpattern from the polished face of the silicon. This change in thepattern is detected.

For the pattern detection, the signal of the reflected pattern issubjected to an IV conversion (i.e., a current-voltage conversion) by aphotodiode in the projecting/receiving unit. Alternatively, thisprojecting/receiving unit may be provided with a high-speed image takingdevice. This image taking device (or an image pickup device) is providedwith a CCD or CMOS camera, for example. The pattern thus obtained issubjected to a pattern recognition treatment. In the example described,the polish end point is detected when the fringe pattern in the patterndisappears.

Thus in this embodiment, by noting the change in the reflected patternin accordance with the material change of the surface of the peripheralportion, the state of the peripheral portion can be precisely decided toimprove the measuring ability.

Thus, it is possible to use the change in the reflection and the changein the reflected pattern. The reflection or the reflected pattern may beseparately used according to the state of the wafer peripheral portionof the object to be measured.

[Substrate Treating Apparatus with Substrate Peripheral PortionPolishing Apparatus]

Next, FIG. 18 shows an example of the substrate treating apparatus whichis provided with the substrate peripheral portion polishing apparatus ofthis embodiment. The substrate treating apparatus 200 is provided with aload/unload unit 202, a first transfer robot 204, a substrate stage 206(or a buffer), a second transfer robot 208, a notch polishing module210, a bevel polishing module 212, a primary rinsing module 214 and asecondary rinsing module 216.

The wafer is transferred by the first transfer robot 204 from theload/unload unit 202 to the substrate stage 206. Then, the wafer issequentially transferred by the second transfer robot 208 to the notchpolishing module 210, the bevel polishing module 212, the primaryrinsing module 214 and the secondary rinsing module 216. The firsttransfer robot 204 returns the rinsed wafer to the load/unload unit 202.

In FIG. 18, the bevel polishing module 212 corresponds to the substrateperipheral portion polishing apparatus thus far described. The substrateperipheral portion measuring device of this embodiment also belongs tothe bevel polishing module 212.

In an applied example of this embodiment, moreover, the wafer evaluatingface is set on the end face or back face of the wafer. The evaluation istimed during or after the polish. For this evaluation, the polishedstate during the polish is monitored, the polish end point during thepolish is detected, or the presence/absence of a defect in the polishedwafer is decided. In the monitor of the polished state of the defectedportion, for example, the end face polish is interrupted at a stagemidway of the end face polish, and the wafer is saved. The remainingdefect (or the residual of the defect polish) is measured. The necessarytime for the additional polish is calculated from the measurement resultso that the additional polish is performed. The wafer is moved againfrom the polish position to the saving position (as indicated at 206 inFIG. 18) for the measurement so that the remaining polish is measured.Thus, a series of operations are carried out by an initial polish, ameasurement at the saving position, an additional polish, a re-save, are-measurement and an additional polish. The measurement and theadditional polish may be repeated. The peripheral portion is polished bythose series operations. The polish time can also be determined.

[Application to Rinsing Apparatus (for Rinsing after Plating)]

Here is described an embodiment for incorporating the substrateperipheral portion measuring device into the rinsing apparatus. In thedescription thus far made, the substrate peripheral portion measuringdevice is incorporated into the substrate peripheral portion polishingapparatus. In the following description, on the other hand, thesubstrate peripheral portion measuring device is incorporated into therinsing apparatus. This rinsing apparatus is exemplified by a rinsingapparatus related to a plating operation, a rinsing apparatus related aCMP (Chemical-Mechanical Polish), and a rinsing apparatus related to anetching operation. The defect and unnecessary substance of theperipheral portion can be detected by measuring the peripheral portionwith the rinsing apparatus.

FIG. 19 shows a plating substrate treating apparatus. This substratetreating apparatus 220 is provided with a substrate cassette 222, afirst transfer robot 224, a substrate stage 226 (or a temporary stage),a second transfer robot 228, a plating bath 230, a rinsing apparatus232, a rinsing liquid and chemicals supply device 234, a platingchemicals supply device 236, a control unit 238 and a display unit 240.

The substrate is transferred by the first transfer robot 224 from thesubstrate cassette 222 to the substrate stage 226. The substrate isfurther transferred by the second transfer robot 228 to the plating bath230 and the rinsing apparatus 232. The plating bath 230 is supplied withthe plating chemicals from the plating chemicals supply device 236. Onthe other hand, the rinsing apparatus 232 is supplied with the chemicalsand the rinsing liquid from the rinsing liquid and chemicals supplydevice 234. The rinsing treatment and the drying treatment are carriedout in the rinsing apparatus 232. The substrate rinsed is returned tothe substrate cassette 222.

In the configuration of FIG. 19, the rinsing apparatus 232 is preferablyprovided with the substrate peripheral portion measuring device. In therinsing apparatus 232, the turning wafer is fed with the rinsing liquidas in the ordinary rinsing apparatus. In this state, the substrateperipheral portion measuring device is provided for measuring the waferperipheral portion.

FIG. 20 shows an example of the configuration of the rinsing apparatus232. In this rinsing apparatus 232, a base unit 250 holds a wafer 252.On the other hand, the base unit 250 is supported by a shaft 254 so thatit turns together with the wafer 252.

The base unit 250 is provided with a wafer holding member. As shown,this wafer holding member is turnably supported by a turning pin. Thisturning pin pivots the portion of the wafer holding member above thecenter of gravity. The wafer holding member is so arranged as is madeparallel to the shaft 254 by its own weight when the wafer stands still.As the shaft 254 turns, a centrifugal force occurs in the wafer holdingmember. By this centrifugal force, the lower portion (i.e., the portionof the wafer holding member below the turning pin) is moved outward andis raised. As a result, the upper portion (i.e., the portion of thewafer holding member above the turning pin) falls down inward to holdand grip the wafer. At least three wafer holding portions are disposedin the circumferential direction.

The wafer 252 is fed on its surface with a rinsing liquid from a rinsingliquid feeding nozzle 256 and with chemicals from a chemicals feedingnozzle 258. The rinsing liquid feeding nozzle 256 is supplied with therinsing liquid from a rinsing line supply line 260, and the chemicalsfeeding nozzle 258 is supplied with the chemicals from a chemicalssupply line 262. Moreover, the wafer turns and liquid supply arecontrolled by a control unit 264, which is connected with a displayinput unit 266.

Typically in the rinsing apparatus of FIG. 20, the rinsing liquid iswater (or pure water) or gas-dissolved water. The rinsing apparatus isproperly provided with a peripheral portion measuring device formeasuring the peripheral portion while being fed with the rinsingliquid. The peripheral portion measuring device may measure theperipheral portion when the chemicals are fed.

[Application to Rinsing Apparatus (Rinsing after CMP)]

FIG. 21 shows a CMP substrate treating apparatus. This substratetreating apparatus 270 is provided with a substrate cassette 272, afirst transfer robot 274, a substrate stage 276 (or a temporary stage),a second transfer robot 278, a polishing module 280, a rinsing apparatus282, a rinsing liquid and chemicals supply device 284, a slurry supplydevice 286, a control unit 288 and a display unit 290.

The substrate is transferred by the first transfer robot 274 from thesubstrate cassette 272 to the substrate stage 276. The substrate isfurther transferred by the second transfer robot 278 sequentially to thepolishing module 280 and the rinsing apparatus 282. The polishing module280 is supplied with the slurry from the slurry supply device 286. Onthe other hand, the rinsing apparatus 282 is supplied with the chemicalsand the rinsing liquid from the rinsing liquid and chemicals supplydevice 284. The rinsing apparatus 282 performs the rinsing operationwith the chemicals and the drying operation. The substrate rinsed isreturned to the substrate cassette 272.

In the configuration of FIG. 21, the rinsing apparatus 282 is properlyprovided with the substrate peripheral portion measuring device. In therinsing apparatus 282, as in the ordinary rinsing apparatus, the turningwafer is fed thereon with the rinsing liquid. The substrate peripheralportion measuring device is provided for measuring the wafer peripheralportion in that state. The configuration of rinsing apparatus may be oneshown in FIG. 20.

[Application to Rinsing Apparatus (Rinsing after Etching)]

FIG. 22 shows a plating substrate treating apparatus. This substratetreating apparatus 300 is used for forming fine copper wiring over thesubstrate. The substrate treating apparatus 300 is provided with asubstrate load/unload unit 302, a first transfer robot 304, a substratestage 306, a second transfer robot 308, a plating device 310, a beveletching device 312, a rinsing apparatus 314, a heat treating (annealing)device 316, a plating liquid tank 318 and a plating liquid analyzingdevice 320.

The substrate is transferred by the first transfer robot 304 from thesubstrate cassette of the substrate load/unload unit 302 to thesubstrate stage 306. The substrate is further transferred by the secondtransfer robot 308 sequentially to the plating device 310 and the beveletching device 312.

The bevel etching device 312 subjects the substrate peripheral portionto an etching treatment. In the bevel etching device 312, for example,the substrate is continuously fed, while being held horizontally andturned, at the central portion on its surface side with an acidsolution. The substrate is continuously or intermittently fed at itscircumferential peripheral portion with an oxidizer solution.

The acid solution may be a non-oxidizing acid such as hydrofluoric acid,hydrochloric acid, sulfuric acid, citric acid or oxalic acid. Theoxidizer solution used is any of ozone water, an aqueous solution ofhydrogen peroxide, an aqueous solution of nitric acid and an aqueoussolution of hypochlorous acid. These may be used in combination. Copperor the like is filmed on or stuck to the circumferential peripheralportion of the substrate. Such copper or the like is abruptly oxidizedin the oxidizer solution, and is etched and dissolved with the oxidesolution fed from the central portion of the substrate so that it isremoved. The oxide solution spreads from the substrate center over theentire surface.

After bevel-etched, the substrate is transferred by the second transferrobot 308 to the rinsing apparatus 314. In this rinsing apparatus 314,the surface of the substrate is rinsed with the chemicals or the rinsingwater such as pure water, and is subjected to a spin drying treatment.

Then, the substrate is further transferred to the heat treating device316. After the heat treatment in the heat treating device 316, thesubstrate is transferred by the second transfer robot 308 to thesubstrate stage 306. Moreover, the substrate is returned by the firsttransfer robot 304 to the substrate load/unload unit 302.

In the configuration of FIG. 22, the rinsing apparatus 314 is properlyprovided with the substrate peripheral portion measuring device. In therinsing apparatus 314, the turning wafer is fed with the rinsing liquid.The substrate peripheral portion measuring device is provided formeasuring the wafer peripheral portion in this state. By this peripheralportion measurement, it is inspected whether or not the portion is leftunetched.

In case the unetched portion is detected by the peripheral portionmeasurement, on the other hand, the wafer may be transferred to thebevel etching device 312 and returned to the etching step. At anotherstep, on the other hand, the unetched portion may be removed. There-treatment or the like according to the measurement result at suchrinsing step may also be carried out in the aforementioned otherembodiments.

[Other Modes]

In the peripheral portion polishing substrate treating apparatus 200, asshown in FIG. 18, the bevel polishing module 212 acting as the substrateperipheral portion polishing apparatus is provided with the substrateperipheral portion measuring device. On the contrary, the substrateperipheral portion measuring device may also be disposed in the notchpolishing module 210. On the other hand, the substrate peripheralportion measuring device may also be disposed in the primary rinsingmodule 214 or the secondary rinsing module 216 acting as the rinsingapparatus. In this modification, the polish is once ended, and theperipheral portion is measured at the rinsing step. If a re-polish isnecessary, the wafer is returned to the polishing step.

In the bevel etching substrate treating apparatus 300, as shown in FIG.22, the rinsing apparatus 314 is provided with the substrate peripheralportion measuring device. On the contrary, the substrate peripheralportion measuring device may also belong to the bevel etching device312. In this case, the peripheral portion is measured during the etchingoperation. The peripheral portion is measured while the wafer is beingfed with the etching chemicals in place of the water. Moreover, theperipheral portion may also be measured after having been cleared of thechemicals, as has been described in the foregoing embodiment.

As exemplified in those examples, the peripheral portion measuringdevice may also be disposed in the etching or polishing removingapparatus so that it may measure the peripheral portion during theremoving operation thereby to detect the end point or the like.Moreover, the peripheral portion measuring device may also be disposedin the rinsing apparatus which is provided together with theaforementioned removing apparatus so that it may perform the measurementwhile the removing treatment being interrupted.

In addition, the substrate peripheral portion measuring device may alsobe disposed in another apparatus. Moreover, the substrate peripheralportion measuring device may be solely disposed. In this modification,the substrate is held and turned for the measurement, and the wafer isfed with a liquid (e.g., water) for the measurement.

The invention has been described in connection with its preferredembodiments. However, the invention should not be limited to theaforementioned embodiments but could naturally be modified within thescope of the invention by those skilled in the art.

EXAMPLES

FIG. 23 and FIG. 24 show the experimental data obtained by using themeasuring device of the invention. The experimental data of FIG. 23 andFIG. 24 are the results of measurements using the laser beam, as shownin the embodiment of FIG. 3. FIG. 23 shows the measurement data of anunpolished product, and FIG. 24 shows the measurement data of a polishedproduct.

In FIG. 23 and FIG. 24, the ordinate indicates the voltage at the timewhen the reflected light is expressed in terms of a DC voltage. Onescale corresponds to 2 volts. The abscissa indicates the position in thecircumferential direction of the wafer. The drawings show the data atthe time when the wafer starts from the notch portion and returns afterfour turns to the notch portion. In other words, the whole range in theabscissa direction corresponds to the four circumferences of the wafer.2.5 scales in the abscissa direction corresponds to one circumference ofthe wafer.

FIG. 23 shows the measurement data of the unpolished product, asdescribed above. In the measurements, a pulsating laser light isprojected from the optical fiber, and the reflected light is received bythe optical fiber.

In FIG. 23, the quantity of the reflected light is small over a widerange. This indicates that the peripheral portion of the wafer iscovered with the film of silicon nitride (SiN).

In FIG. 23, moreover, high spike signals are found. In some portions,the intensities of the reflected light are locally high. These portionsindicate that the wafer is locally polished. At these portions, thewafer peripheral portion is polished for experiments so that the siliconnitride is damaged to expose the silicon (Si) locally to the outside.The exposure of silicon raises the intensities of the reflected signal.

FIG. 24 shows the measurement data of the polished article. In FIG. 24,the quantity of reflected light is large over a wide range. Thisindicates that the film of the silicon nitride of the wafer peripheralportion is polished away to expose the silicon (Si) to the outside.Observing the damaged portions in FIG. 23, the silicon nitride aroundthe damage is removed so that the damage disappears.

By comparing the reflected lights before and after the polish, as shownin FIG. 23 and FIG. 24, it is possible to detect the polish end point(i.e., the end of the polish). For deciding the polish end point, as hasalready been described, it is arbitrary to use the change of a relativeoptical quantity, the change of an absolute value or the change of adifferentiated value.

While there has been described what is at present considered to bepreferred embodiments of the invention, it will be understood thatvarious modifications may be made thereto, and it is intended thatappended claims cover all such modifications as fall within the truespirit and scope of the invention.

INDUSTRIAL APPLICABILITY

The invention can measure the peripheral portion of a substrate and canbe usefully employed in substrate manufacturing facilities.

1. A substrate peripheral portion measuring device for measuring thestate of the peripheral portion of a substrate, comprising: a wavetransceiver for transmitting a transmission wave to said peripheralportion while a liquid is being fed to said substrate and is flowing onsaid peripheral portion, and for receiving a reflected wave from saidperipheral portion; and a received wave processing unit for processingthe signal of said reflected wave to decide the state of said peripheralportion.
 2. A substrate peripheral portion measuring device inaccordance with claim 1, further comprising: a passage forming portionenclosing said peripheral portion for forming a passage to feed saidliquid onto said peripheral portion; wherein the wavetransmitting/receiving portion of said wave transceiver is arranged insaid passage.
 3. A substrate peripheral portion measuring device inaccordance with claim 2, wherein the wall face of said passage has awave collecting face shaped to further reflect said reflected wavethereby to collect said reflected wave; and wherein said wavetransceiver has a portion for receiving said reflected wave at aposition where said reflected wave is collected.
 4. A substrateperipheral portion measuring device in accordance with claim 1, furthercomprising: a liquid removing unit for blowing away said liquid fromsaid peripheral portion; wherein said wave transceiver transmits saidtransmission wave to the place where said liquid is blown away by saidliquid removing unit.
 5. A substrate peripheral portion measuring devicein accordance with claim 1, further comprising: a liquid blocking unitenveloping said peripheral portion partially for blocking the arrival ofthe liquid at said peripheral portion; wherein said wave transceiver isdisposed to transmit/receive the wave through said liquid blocking unit.6. A substrate peripheral portion measuring device in accordance withclaim 1, wherein said received wave processing unit decides the state ofsaid peripheral portion on the basis of the relative change of saidreflected wave accompanying the change of said substrate.
 7. A substrateperipheral portion measuring device in accordance with claim 1, whereinthat said received wave processing unit decides the state of saidperipheral portion on the basis of the time differentiation of saidreflected wave accompanying the change of said substrate.
 8. A substrateperipheral portion measuring device in accordance with claim 1, whereinsaid received wave processing unit decides the state of said peripheralportion by performing a frequency analysis of said reflected wave.
 9. Asubstrate peripheral portion measuring device in accordance with claim1, wherein said received wave processing unit performs an end pointdetection of the processing of said peripheral portion.
 10. A substrateperipheral portion measuring device in accordance with claim 1, whereinsaid received wave processing unit monitors the state of the treatingprocedure of said peripheral portion.
 11. A substrate peripheral portionmeasuring device in accordance with claim 1, wherein said received waveprocessing unit detects a defect of said peripheral portion.
 12. Asubstrate peripheral portion measuring device in accordance with claim1, wherein said wave transceiver transmits at least one of a laserlight, a while light, a microwave, an ultrasonic wave and an alternatingmagnetic field signal as a transmission wave to said peripheral portion.13. A substrate peripheral portion measuring device in accordance withclaim 1, wherein a plurality of said wave transceivers are arrangedalong the peripheral portion of said substrate.
 14. A substrateperipheral portion measuring device in accordance with claim 1, whereinthe substrate peripheral portion to be measured has a silicon nitridefilm, a silicon oxide film, a poly-silicon film, a barrier film of Ta,TaN, TiN, Ti or the like, or a metal film of Cu, W or the like.
 15. Asubstrate peripheral portion measuring device in accordance with claim1, wherein said received wave processing unit clears the signal of saidreflected wave of noise components.
 16. A substrate peripheral portionmeasuring device in accordance with claim 1, wherein said wavetransceiver is configured to project a laser light and to receive areflected light; and wherein a beam size is set according to themovement of the turning wafer.
 17. A substrate peripheral portionmeasuring device in accordance with claim 1, further comprising: amodulation unit for modulating the laser light projected as saidtransmission wave by said wave transceiver; and a synchronism detectingunit for detecting the reflected light received as said reflected waveby said wave transceiver, in synchronism with the modulation by saidmodulation unit.
 18. A substrate peripheral portion measuring device inaccordance with claim 1, wherein said wave transceiver is configured tosend transmission waves of a plurality of kinds; and wherein saidreflected wave processing unit is configured to process reflected wavesof a plurality of kinds received by said wave transceiver.
 19. Asubstrate peripheral portion measuring device in accordance with claim18, wherein the kind of transmission wave to be used for the measurementis changed according to the material of said peripheral portion of saidsubstrate.
 20. A substrate peripheral portion measuring device inaccordance with claim 1, wherein said received wave processing unitdecides the state of said peripheral portion on the basis of zone dataobtained from reflected waves of measurement zones disposed along theouter circumference of said substrate.
 21. A substrate peripheralportion measuring device in accordance with claim 20, wherein saidreceived wave processing unit decides the state of said peripheralportion by comparing the zone data obtained from said measurement zones.22. A substrate peripheral portion measuring device in accordance withclaim 1, wherein said received wave processing unit decides the state ofsaid peripheral portion on the basis of the change of the reflectionaccording to the material change of the surface of said peripheralportion accompanying the treatment of said substrate.
 23. A substrateperipheral portion measuring device in accordance with claim 1, whereinsaid received wave processing unit decides the state of said peripheralportion on the basis of the pattern change of said reflected waveaccording to the material change of the surface of said peripheralportion accompanying the treatment of said substrate.
 24. A substrateperipheral portion measuring device in accordance with claim 1, whereinsaid substrate peripheral portion measuring device belongs to asubstrate peripheral portion polishing apparatus for polishing theperipheral portion of a substrate and measures the polished state of theperipheral portion of the substrate being polished.
 25. A substrateperipheral portion measuring device in accordance with claim 1, whereinsaid substrate peripheral portion measuring device belongs to asubstrate treating apparatus provided with a substrate peripheralportion polishing apparatus for polishing the peripheral portion of asubstrate and measures the polished state of the peripheral portion ofthe substrate being polished.
 26. A substrate peripheral portionmeasuring device in accordance with claim 1, wherein said substrateperipheral portion measuring device belongs to a substrate rinsingapparatus and measures the polished state of the peripheral portion ofthe substrate being rinsed.
 27. A substrate peripheral portion measuringdevice in accordance with claim 1, wherein said substrate peripheralportion measuring device belongs to substrate treating apparatusprovided with a substrate rinsing apparatus and measures the polishedstate of the peripheral portion of the substrate being rinsed.
 28. Asubstrate peripheral portion polishing apparatus comprising: a substrateholder for holding a substrate; a substrate turning unit for turningsaid substrate; a liquid supply unit for supplying said substrate with aliquid; an peripheral portion polishing unit for polishing theperipheral portion of said substrate while being supplied with saidliquid; a wave transceiver for transmitting a transmission wave to saidperipheral portion while said liquid is flowing on said peripheralportion, and for receiving a reflected wave from said peripheralportion; a received wave processing unit for processing the signal ofsaid reflected wave to decide the polished state of said peripheralportion; and a control unit for controlling the polish of saidperipheral portion in accordance with the polished state of saidperipheral portion obtained by said received wave processing unit.
 29. Asubstrate peripheral portion polishing apparatus in accordance withclaim 28, further comprising: a passage forming portion enclosing saidperipheral portion for forming a passage to feed said liquid onto saidperipheral portion; wherein the wave transmitting/receiving portion ofsaid wave transceiver is arranged in said passage.
 30. A substrateperipheral portion polishing apparatus in accordance with claim 29,wherein the wall face of said passage has a wave collecting face shapedto further reflect said reflected wave thereby to collect said reflectedwave; and wherein said wave transceiver has a portion at a position,where said reflected wave is collected, for receiving said reflectedwave.
 31. A substrate peripheral portion polishing apparatus inaccordance with claim 28, further comprising: a liquid removing unit forblowing away said liquid from said peripheral portion; wherein said wavetransceiver transmits said transmission wave to the place where saidliquid is blown away by said liquid removing unit.
 32. A substrateperipheral portion polishing apparatus in accordance with claim 28,further comprising: a liquid blocking unit enveloping said peripheralportion partially for blocking the arrival of the liquid at saidperipheral portion; wherein said wave transceiver is disposed totransmit/receive the wave through said liquid blocking unit.
 33. Asubstrate peripheral portion polishing apparatus in accordance withclaim 28, wherein said received wave processing unit detects the polishend point of the peripheral portion; and wherein said control unit endsthe polish of said peripheral portion when the polish end point of saidperipheral portion is detected.
 34. A substrate peripheral portionpolishing apparatus in accordance with claim 28, wherein said receivedwave processing unit monitors the state of the polishing procedure ofthe peripheral portion; and wherein said control unit controls thepolishing condition of said peripheral portion in accordance with thestate of the polishing procedure of said peripheral portion.
 35. Asubstrate peripheral portion polishing apparatus in accordance withclaim 34, wherein said control unit controls at least one of the turningspeed of said substrate, the pushing force of the polishing tool to saidperipheral portion, the feed movement of the polishing tape, the feedspeed of the polishing tape, the relative movement of the polishing headwith respect to the substrate, the relative moving speed of thepolishing head with respect to the substrate, and the feed rate of saidliquid.
 36. A substrate peripheral portion polishing apparatus inaccordance with claim 28, wherein said received wave processing unitdecides whether or not the peripheral portion is defective.
 37. Asubstrate peripheral portion polishing apparatus in accordance withclaim 28, further comprising: an abnormality detecting unit fordetecting that a polish abnormality has occurred when the polish endpoint is not detected even if the polishing time reaches a predeterminedmaximum polishing time; wherein said control unit stops the polish whenthe abnormality is detected by said abnormality detecting unit.
 38. Asubstrate peripheral portion polishing apparatus in accordance withclaim 28, further comprising: an abnormality detecting unit fordetecting that a polish abnormality has occurred when the waveform ofthe reflected wave is abnormal; wherein said control unit stops thepolish when the abnormality is detected by said abnormality detectingunit.
 39. A substrate peripheral portion polishing apparatus inaccordance with claim 28, further comprising: a tool exchange informingunit for informing the arrival of an exchanging timing of a polishingtool when the polishing rate obtained from said reflected wave lowers toa predetermined tool exchanging threshold rate.
 40. A substrateperipheral portion polishing apparatus in accordance with claim 28,wherein said wave transceiver is configured to send a plurality of kindsof transmission waves; and wherein the kind of said transmission wave tobe used for the measurement is changed according to the proceedingsituation of the polishing procedure determined from said reflectedwave.
 41. A substrate peripheral portion polishing apparatus inaccordance with claim 28, wherein said wave transceiver is configured tosend a plurality of kinds of transmission waves; and wherein the kind ofsaid transmission wave to be used for the measurement is changed inassociation with the change of the polishing condition by said controlunit.
 42. A substrate peripheral portion polishing apparatus inaccordance with claim 28, wherein said control unit controls the polishof said substrate on the basis of said polishing state and the controlparameter of an peripheral portion polishing tool.
 43. A substrateperipheral portion polishing apparatus in accordance with claim 42,wherein said control unit interchanges the control based on said controlparameter and the control based on said polishing state, in accordancewith the progress of the polishing procedure of the substrate.
 44. Asubstrate peripheral portion polishing apparatus in accordance withclaim 28, wherein said received wave processing unit detects the polishend point by comparing the polish end point target set according to thereflected wave at an initial polishing stage and the reflected waveobtained from said wave transceiver.
 45. A substrate peripheral portionpolishing apparatus in accordance with claim 28, further comprising: anend time setting unit for setting the polish end time, at which thepolish end point is reached, on the basis of a reference time till apredetermined reference polishing state is obtained in the polishingprocedure.
 46. A substrate rinsing apparatus comprising: a substrateholder for holding a substrate; a substrate turning unit for turningsaid substrate; a liquid supply unit for supplying said substrate with aliquid; a wave transceiver for transmitting a transmission wave to theperipheral portion of said substrate while said liquid is flowing onsaid peripheral portion, and for receiving a reflected wave from saidperipheral portion; and a received wave processing unit for processingthe signal of said reflected wave to decide the polished state of saidperipheral portion.
 47. A substrate peripheral portion measuring methodfor measuring the state of the peripheral portion of a substrate,including: transmitting a transmission wave to said peripheral portionwhile a liquid is being fed to said substrate and is flowing on saidperipheral portion; receiving a reflected wave from said peripheralportion; and processing the signal of said reflected wave to decide thestate of said peripheral portion.
 48. A substrate peripheral portionpolishing method including: holding a substrate; turning said substrate;supplying said substrate with a liquid; polishing the peripheral portionof said substrate while said liquid is being supplied; transmitting atransmission wave to said peripheral portion while said liquid isflowing on said peripheral portion; receiving a reflected wave from saidperipheral portion; processing the signal of said reflected wave todecide the polished state of said peripheral portion; and controllingthe polish of said peripheral portion in accordance with the polishedstate of said peripheral portion.
 49. A substrate rinsing methodincluding: holding a substrate; turning said substrate; supplying saidsubstrate with a liquid; transmitting a transmission wave to saidperipheral portion while said liquid is flowing on the peripheralportion of said substrate; receiving a reflected wave from saidperipheral portion; and processing the signal of said reflected wave todecide the polished state of said peripheral portion.